Apparatus for the manufacture of cellulose.



E. SCHAUFFELBERGER. APPARATUS FOR THE MANUFACTURE OF. CELLULOSE.

APPLICATION FILED MAY 25. 1917a lPatented Oct. 22 1918.

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EH11; SGHAUFFELBEBGER, 0F, PUTNEY, LONDON, ENGLAND.

Specification of Letters Patent.

i TUS FOR THE MANUFACTURE 013 CELLULOSE.

Patented @cti 22, 1918.

Application filed May 25, 1917. 'Serial No, 170,982.

able for the process of treatment or preparation which consists in digesting bamboo, esparto, wood pulp or other suitable fibrous material by means of heated liquor (and by liquor is meant any liquid, whether acid or alkaline, which may be used for this purpose) in a digester, it is also suitable for similar operations in which a material is to be extracted from a fibrous base by a process of-indirect cooking or digesting.

In such processes as hitherto carried out great difficulties have been experienced due to the fact that no adequate means have been provided for preventing the clogging and incrustation of the pumping and heating devices employed by fibrous matter and by scum or other impurities carried by the circulating liquor. Attempts have been made to overcome these difliculties by providing a form of apparatus in which the liquor is circulated through the digester in a downward direction, while the digester is fitted with an internal strainer situated near the lower part of the digester for the purpose of retaining the fibrous matter within the digester and preventing chips from being drawn into the pumping and heating devices. This ar-- rangement, w-wever, sufiers from the disadvantage that the internal strainer is under conslderable pressure due to the supermcumbent head of pulp and such pressure as may be necessary to force the liquid through the pulp column, the result being that the pulp in the immediate vicinity of the strainer is broken up under such pressure and is forced throu h the apertures in the strainer so that the dlfiiculties above noted are not in any way obviated and, moreover, the product produced is not in any way separated from the scum or other impurities that commonly float in or on the liquor, with the result that serious difliculties are encountered in the later processes of treatment. I

The object of the present invention is to provide lmprovementsin the carrying out of such operations as willremove the above difliculties and disadvantages, and according to my invention I interpose in th system means such that the scum or other im purities carried by the liquor will be separated therefrom before the liquor passes to the heating and pumping devices forming.

part of the system.

The invention also comprises other details and arrangements hereinafter described )r indlcated.

The accompanying drawings illustrate more or less diagrammatically one convenient form of apparatus for carrying out the invention.

In carrying my invention into effect in one convenient manner when applying it, for example, to the preparation of cellulose from bamboo, e'sparto, wood pulp or other suitable material, I provide a digester a which may be of steel or other suitable material and of any usual or desired'size and shape but preferably having its upper and lower portions 6 a tapered or conical, and to the lower part c of the digester I secure the delivery pipe cl from the centrifugal pump e or other circulating device that may be employed, the draw-off pipe 7 for the liquor being situated in the upper part of the digester so that in contradistinction to known processes the liquor is forced through the digester (which has been previously filled with the material to be treated) in an upward direction. The arrangement is such that the scum and other impurities are forced into the upper portion 1) o'f the digester by the rising liquor and the latter after leaving the digester is caused to pass through a separating or cleansing device or devlces of suitable construction before passing to the heater 9 and thence to the suction pipe of the pump 6.

In the construction illustrated the separating device comprises a vessel it of suitable size and shape, to the lower part of which is fitted the draw-ofi' pipe f from the digester, this pipe communicating with a bell-mouthed or trumpet shaped device '5 arranged within the outer vessel or container h and having its diameter expanding in the direction of flow so that the efiect of this arrangement is that the scum and impurities contained in the liquor Will heater 9 which may be of the tubular or other suitable form.

If desired or necessary Imay arrange in the upper part of the digester a strainer :12 having relatively large apertures so that while not liable to become clogged will yet prevent the egress of large chips from the digester, and where-necessary I may provide in conjunction With the separator It and preferably superposed thereon a gas separator such as m of the spiral screen or other known or desired type for the purposeof providing for the separation from the liquor of any gases that may accumulate in the digester during the operation.

Furthermore, I may if necessary provide in the interior of the digester and surrounding the inlet a a screen 0 of suitable form in order to keep the materialclear of the inlet when the apparatus is standing, it being-obvious that during operation the inlet will be automatically maintained free by the pressure of delivery of the liquor necessary to force the same through the column of pulp" By suitable manipulation of the valves also the pressure of the liquor in the heater or in any other part of the apparatus may be artificially raised thus raising the boiling point and reducing the formation of bubbles in the heater tubes so that the clogging of the heater will be thus prevented or minimized.

It will be obvious thatthe apparatus is applicable also when an added substance or substances is or are introduced into the liquor such for example, when precipitating lime in the separator.

Having now described my invention, what-I claim asnew and desire to secure by Letters Patent is 1. Apparatus for use in the manufacture of cellulose, comprising a digester, a separator, a heater, and a pump, a feed pipe leading from said pumpto the bottom of said digester, a draw-ofi' pipe leading from the top of said digester to the bottom of said separator, means for carrying the liquid from said delivery pipe to the upper part of said separator, an outlet pipe leading from the bottom of said separator to the said heater, and a pipe leading from said heater to said pump, substantially as described.

2. Apparatus for use in the manufacture heater to said taaaeea of cellulose, comprising a digester provided with a strainer at the top and bottom thereof, a separator, a heater, and a pump, a feedpipe leading from said pump to the bottom of said digester, a draw-off pipe leading from the top of said digester to the bottom of said separator, a gas separator mounted above said first-named separator, an escape pipe for gas connected thereto, means for carrying the liquid from said delivery pipe to the upperpart of said separator, an outlet pipe leading from the bottom of said separator to the said heater, and a pipe leading from said heater to said pump, substantially as described.

3. Apparatus for use in the manufacture of cellulose, comprising a digester, a plurality of separators, a heater, and a pump, a feed pipe leading from said pump to the bottom of said digester, a draW-ofl" pipe leading from the top of said digester to the bottom of said separators, means for carrying the liquid from said delivery pipe to the upper part of said separators, an outlet pipe leading from the bottom of said separators to the said heater, and a pipe leading from said heater, to said pump, substantially as described.

4:. Apparatus for use in the manufacture of cellulose, comprising a digester provided with a strainer at the top and bottom thereof, a plurality of separators, a heater, and a pump, a feed pipe leading from said pump to the bottom of said digester, a draW-ofi' pipe leading from the top of said digester to the bottom of said separators, gas separators mounted above said first named separators, and escape pipes for gas connected thereto, means for carrying the liquid from said delivery pipe to the upper part of said separators, an outlet pipe leading from the bottom of said separators to the said heater, and a pipe leading from said heater to said pump, substantially as described.

5. Apparatus for use in the manufacture of cellulose, comprising a digester, a separator, a heater, and a pump, a'feed pipe leading from said pump to the bottom of said digester, a draW-ofl pine leading from the top of said digester to the bottom of said separator, a bell mouth inlet tube connected to said escape pipe for carrying the liquid from said delivery pipe to the upper part of said separator, an outlet pipe leading from the bottom of said separator to the said heater, and a pipe leading from said pump, substantially as described.

6. Apparatus for use in the manufacture of cellulose, comprising a digester provided with a strainer at the top and bottom thereof, a separator, a heater, and a pump, a feed pipe leading from said pump to the bottom of said digester, a draw-ofl' pipe leading from the top of said digester to the bottom above sai first-named separator, an escape leading from said heater to said pump, pipe for gas connected thereto, a bell mouth stantially as described.

inlet tube connected to said escape pipe for In testimony whereof I have signed my t carrying the hquld from sald delivery pipe name to this specification.

to the upper part of said separator, an outlet pipe leading from the bottom of said. I E. SCHAUFFELBERGER.

of said se arator, a gas separator mounted separator to the said heater, and. n pi? su 

